Method and means for removing carbon deposits



atented Sept. 5, 1933 UNITED ii? METHOD IHEANS FOR REMOVING CARBONDEPOSITS Wheeler G. Lovell and Thomas A. Boyd, Detroit, Mich., assignorsto General Motors Research Corporation, Detroit, Mich., a corporation oiDelaware No Drawing. Application August 28, 1929 Serial No. 389,092

Claims.

This application relates to the removal of carbon deposits from thecombustion chambers of internal combustion engines, and its princi- 5pal objects are to employ compounds particularly suitable for thispurpose and a process adapted to employ these compounds at their highestefi'iciency.

We have found that unsaturated aliphatic ethers which are varnishremovers such as diallyl ether, propargyl ethyl ether and allyl ethylether are particularly useful in removing carbon deposits, and that thebest method of using them is to apply them to carbon coated parts whichhave been heated preferably to a temperature above 150 F, the optimumconditions for water cooled engines being at approximately the boilingpoint of water. We may also use with allyl ethyl ether a mixture ofbenzol and alcohol,

0 or other low boiling varnish remover, which apparently increases thesolvent action of these ethers not only by reducing the viscosity, butalso because they are lower boiling and tend to keep the liquid incontact with the carbon in a mild state of agitation.

As a specific example we may use in each cylinder of an ordinary sixcylinder engine c. c. of a mixture comprising by volume 40 parts a1- lylethyl ether, 30 parts of benzol, and 30 parts 39 of ethyl alcohol. Theengine is operated until the temperature of the metal parts of thecombustion chamber is at least 150 F. when the mixture is injected orotherwise introduced into the cylinders and the engine stopped. Themixture is permitted to remain in the cylinders for about two hours,more or less, depending upon the nature of the carbon deposit, duringwhich time the gummy binder is softened or dissolved. Then the engine isstarted and the loosened 40 deposit is gradually blown out the exhaust.

When cleaning the parts by hand they may be heated, the solvent applied,and'when the binder is softened the deposit may .be wiped ofi.

It is within the scope of the present invention 60 to employ anyunsaturated aliphatic ether which is a varnish remover and to vary theproportions according to the compound used and the specific conditions,and the unsaturated ether may be used alone.

We claim:-

1. The process of removing carbon deposits from the combustion chamberof an internal combustion engine which comprises applying to the carbondeposit unsaturated aliphatic ethers which are varnish removers, andremoving the carbon deposit.

2. The process of removing carbon deposits from the combustion chamberof an internal combustion engine which comprises heating the 7 coatedparts, applying to the carbon deposit unsaturated ahphatic ethers whichare varnish removers, and a low boiling varnish remover, and removingthe carbon deposit.

3. The process of removing carbon deposits 0 from the combustion chamberof an internal combustion engine which comprises heating the coatedparts to above 150 F., applying to the carbon deposit allyl ethyl ether,benzol and alcohol, and removing the carbon deposit.

4. A composition of matter for removing carbon deposits from internalcombustion engines comprising an unsaturated aliphatic ether whichremoves varnish, and a low boiling varnish remover.

5. A composition of matter for removing carbon deposits from internalcombustion engines comprising allyl ethyl ether, benzol and alcohol.

WHEELER G. LOVELL. THOMAS A. BOYD.

